Floating apps and FileBrowser has 2 big bugs or Issue altogether
File browser has 1bug at window mode and all Floating apps has 1issue or bug at full-screen mode :
1- In full-screen mode of all your floating apps like file browser can not view and access to another your opened floating app at window mode, You must support feature "being on top of all full screen apps" if other floating apps are opened at window mode!!!
of course If i minimize the window app and then run full screen other app i can access and view minimize app at window mode after restore
2- In Window mode of File browser there is a big bug And it is unsupporting keep and remember scrolling last position in folder with long files or folders list, if scroll down to middle of the list view, then you will see scroll bar backing to first of the folder list after file browser get disactive by tapping on another floating app and retapping again on file browser and active its window!!!
This is very important for me especially I constantly need cut copy renaming synchronization files in a folder via your file browser and compare it at a same time with texts typed in a text editor, or scroll down and up in a folder to play a file at music or video player or Document viewer..
Please fix these two bugs soon, These two issues disappoint user from your product completely very soon and motivated her to leave your apps into featured apps.
see snapvideo (I enabled show touches at my Android settings to showing visual feedback for touch Interactions)
Unfortunately, these are technical limitations of the windowing system.